ABSTRACT
BACKGROUND: Cell free DNA (cfDNA) has shown promising utility as prognostic biomarker for patients with colorectal cancer (CRC), with an ongoing need to optimize and validate the laboratory methodology. Here, we report our optimization and validation of a direct fluorescent assay and display the potential utility in patients with colorectal cancer. METHODS: Plasma cfDNA was analyzed by a direct fluorescent assay (DFA) and compared to quantification by droplet digital PCR (ddPCR). For clinical validation, baseline blood samples were available for a total of 273 patients from six different Nordic trials, covering patients with locally advanced rectal cancer (nâ¯=â¯176, cohorts Aâ¯+â¯B), liver limited metastatic CRC (nâ¯=â¯75Câ¯+â¯D) and wide spread metastatic CRC (nâ¯=â¯22 Eâ¯+â¯F). RESULTS: Validating the DFA analysis with ddPCR revealed a strong correlation with an R2 of 0.81. For the clinical cohorts, the levels of cfDNA were: 0.8â¯ng/uL (95%CI 0.75-0.83) (Aâ¯+â¯B), 0.93â¯ng/uL (95%CI 0.86-1.02) (Câ¯+â¯D) and 1.2â¯ng/uL (95%CI 0.85-1.47) (Eâ¯+â¯F), respectively (pâ¯<â¯0.01). All cohorts of colorectal cancer had higher levels of cell free DNA than healthy individuals (nâ¯=â¯94) (pâ¯<â¯0.01). CONCLUSION: Analysis of cell free DNA by a direct fluorescent assay could be an attractive laboratory option for a rapid inexpensive quantification of cell free DNA.
Subject(s)
Cell-Free Nucleic Acids/blood , Colorectal Neoplasms/blood , DNA, Neoplasm/blood , Fluorescent Antibody Technique, Direct , Cell-Free Nucleic Acids/genetics , Cohort Studies , Colorectal Neoplasms/genetics , DNA, Neoplasm/genetics , Humans , Polymerase Chain ReactionABSTRACT
A total of 67 patients with treatment resistant chronic venous ulcers were admitted to hospital for 6 weeks of bed rest and daily dressings. The patients came from a rural area in Poland with poor socioeconomic conditions. They were randomized to treatment with either standard dressings or with cadexomer iodine. After 6 weeks all but four patients had shown a clear reduction of ulcer area; the mean reduction was 54% within the former group and 71% with cadexomer iodine. The latter treatment was significantly more effective than the standard hospital dressings in debriding the ulcer, accelerating healing and reducing pain. Elevation of serum concentrations of protein-bound iodine occurred after treatment with cadexomer iodine in patients with large ulcers, but tests of thyroid function showed no changes associated with the use of cadexomer iodine. It is concluded that cadexomer iodine significantly accelerates the healing of chronic, infected, treatment-resistant, venous ulcers in hospitalized patients.
